What problem does it solve? TanStack Start codebases mix isomorphic routes, server functions, and UI in ways that quickly become tangled: oversized route files, types declared inline, database access leaking into loaders, and accidental edits to the generated route tree. This Skill enforces a consistent modular architecture so Start projects stay maintainable as they grow. ## Core Features & Use Cases - Architecture enforcement: Applies per-type line budgets (route components < 50, server functions < 40, hooks < 30), mandates types in src/interfaces/, JSDoc on every export, and forbids barrel exports and feature-to-feature imports. - Server/client boundary rules: Ensures DB access, secrets, and filesystem work live behind createServerFn or createServerOnlyFn, never in a bare isomorphic loader. - Ready-to-use templates and references: Ships templates for routes, server functions, interfaces, and hooks, plus deep-dive references on SRP, ISP, DIP, and directory layout. - Use Case: When a route file grows past 90 lines mixing types, a DB query, and UI, use this Skill to split it into interfaces/, server/, functions/, and components/ following the modular structure. ## Quick Start Review my TanStack Start project structure and refactor any oversized routes or server functions to follow SOLID principles.
